A British sniper currently holds the publicly known record for a confirmed kill shot. As a Corporal of Horse in the British Army, Craig Harrison used a .338 caliber L115A3 Long Range Rifle to shoot a man from 2,707 yards (1.54 miles) in Afghanistan in 2009.
Variability is a measure of the spread of a data set. Learn more about the different measures of variability including the range, variance, and standard deviation, and how they are used in the field of Psychology.
Variability can also be defined in terms of how close the scores in the distribution are to the middle of the distribution. Using the mean as the measure of the middle of the distribution, the variance is defined as the average squared difference of the scores from the mean. The data from Quiz 1 are shown in Table 1. The mean score is 7.0. Therefore, the column Deviation from Mean contains the score minus 7.